In hockey, when things are going especially poorly for a team and morale is low, a coach can "lose the dressing room," which is to say that he can lose his authority among the players (and thus his ability to coach). Usually the relationship between the coach and his players is incurably poisoned in such a case—those players will never play their hearts out for that coach again—and this means that one or the other has to go—which means, in turn, that the coach is done "because you can't fire the whole team." Fortunately for those of us who aspire to become university teachers, there's the possibility of tenure and the fact that we "fire the whole team" at the end of every semester. But, more seriously, a teacher never wants to lose his credibility with the students, and, as Lee Trepanier and Phil Hamilton have pointed out in their comments on my last post, coming off as ideological or dogmatic is likely to have precisely this result. The question is, why?
My first inclination is to suggest that students will resist an ideological professor because they want to understand things for themselves. They want to know why they should think something, not just that they should think it. For this reason, it's not enough to tell students something—a teacher has to show it to them. Fair enough. Most teachers realize that true learning depends on students gaining an understanding of the materials from the inside out, which means that students must be allowed to think things through on their own terms. Students know this too; thus, if they sense that their teacher is trying to circumvent the process, they'll usually resist (despite their oft-demonstrated inability to distinguish between "thinking" something and "feeling" it, most students have a resilient capacity for resisting "indoctrination").
I think there's a lot of truth in that first answer, but, upon reflection, it seems to me that there's another, deeper reason: students recognize ideological and dogmatic thinking as a sign of incompetence. "Incompetence" is a strong word, so let me explain. Since the teacher-student relationship is a free one, it depends on trust. Teachers must trust that their students are interested in and willing to pursue the truth about things, and students must be able to trust that their teacher is willing and able to lead them there (or at least in that direction). Of course, some students won't live up to their end of the bargain, and I'm not sure that a teacher can do very much about that, but he can certainly ensure that he does his part. Simply put, this means understanding the materials. A teacher should understand his subject well enough that he can allow the materials to take on a life of their own and still be able to lead the students through them. He should have the capacity to steer the students toward truth by taking them through the logic of an argument or an interpretation "at arm's length." When a teacher is unable to do this—when he's unable to guide the students while addressing objections, answering questions, or explaining why alternative arguments don't go through—he may attempt to assert control over the materials (i.e., force the argument or interpretation in a particular direction) by resorting to ideological or dogmatic thinking. That is to say, if he's unable to lead the students through the materials in a scientific manner, he may try to do so by asserting unsupported opinions. I think students can sense this when it happens, and I think it explains why they will reject an ideological or dogmatic professor. They simply don't trust what the professor is telling them.
What this means is that, like hockey coaches, teachers rely on both formal and informal sources of authority—the latter probably being the most important. While it's true that students owe a certain deference to their teachers, this doesn't mean that they have to open up their minds to them. Whether they do that or not depends on whether they trust their professors, and that depends on whether a teacher can demonstrate that he deserves to be regarded with authority. Earning that regard depends on both knowledge and honesty: a teacher should know his subject, but he should also admit what he doesn't know and recognize that his authority ends where his knowledge (or at least his ability to communicate it) does.
That’s how it seems to me anyway. I'd be interested to hear what some more experienced teachers have to say.